Delta Species Pokémon are a special kind of Pokémon whom dwell within the region of Holon. These Pokémon are unique in that they have a type that completely differs from their usual typing. Originally, the Delta Species Pokémon were dual-typed and part Metal type. However, they soon started to be single typed Pokémon.

Delta Species Pokémon have also been Pokémon-ex as well as Pokémon . The Delta Species Pokémon all had a type which matched their Alternate Colour.